Note: Descriptions are shown in the official language in which they were submitted.
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PIPETTE TIP RACK LOADER
BACKGROUND OF THE INVENTION
The invention relates to a device for loading
pipette tips that have been positioned in a flat into
S an upstanding pipette rack for use in the laboratory.
In recent years, the use of pipettes and pipette
tips has become widespread because of the requirements
to maintain sterile or aseptic conditions while con-
ducting various laboratory tests. This usage occurs
both in the medical testing laboratory, wherein fluid
samples taken from human beings are tested in various
laboratory procedures, and extends to the biomedical
and bioengineering laboratories where research is done
in advanced areas of biology and the like.
The requirement to maintain an aseptic condition
is paramount in that contamination of any sort in the
biological laboratory can result in improper findings
relating to the particular area being investigated.
In the medical field, it is even more important as the
tests performed may very well result in having a
lasting impact on the patient upon which the tests
were performed. In the last ten or fifteen years, the
requirement for tests for HIV or Human Immuno-
deficiency Virus, has put even more severe pressure on
medical testing laboratories. A false positive test,
of course, results in severe hardship on the patient,
while a false negative test would not only have impact
on the patient, but could result in more widespread
disease. From the laboratory technician's standpoint,
contact with contaminated specimens that are being
tested is, of course, of vital concern as the labora-
tory technician could suffer from the very disease
that he or she is attempting to investigate should
contamination become widespread.
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Accordingly, laboratories have reached the point
that laboratory equipment, particularly the interface
of the equipment and the sample, is simply not handled
by a human being after sterilization.
Pipettes and pipette tips are used, of course,
and have been used for a number of years, to obtain
small, measured samples of whatever is to be tested.
Until about 20 years ago, pipettes were a single
entity made of glass, and were cleaned and sterilized
after each use. About 20 years ago, the plastic
pipette tip and a mechanical pipettor came on the
market and rapidly achieved widespread use. The
single pipettor used a pipette tip approximately 2 to
2~ inches (5 to 6.25 cm) long that is tapered in its
farm so that it would fit on a tapered end of the
pipettor. The pipettor has a piston action that
creates a suction within the pipette tip so that
fluids can be drawn up into the pipettor. The
advantage of the mechanical pipettor is that the
plastic tip can be thrown away as that is the only
area that the sample touched. Since great numbers of
pipette tips are used, these pipette tips are usually
sold in racks. Pipette tips racks appeared in the
market concurrently with the pipette tips, but always
presented a problem of how to Load the pipette tips
into the racks. While methods have been devised to
load tips into the racks, the concern for the
environment his caused a movement in the laboratories
to reuse pipette tip racks which, in the past, were
thrown away once they were empty. Accordingly, it has
become the practice of the laboratories to buy racks ,
loaded with pipette tips and as the racks are emptied,
pipette tips sold in bulk are reloaded into the racks ,
by hand.
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The manual loading of pipette tips is tedious and
time-consuming. Thus, in recent months, the menu
facturers of pipette tips have attempted to utilize
schemes for loading pipette tips into the trays for
' 5 use in laboratories.
The requirement for a tray is present because the
present pipettors are multiple-channel pipettors; that
is, they mount either eight or twelve pipette tips at
a time so that eight or twelve samples can be taken
concurrently. The rack sits on the laboratory bench
and the pipettor is forced down onto a row of pipette
tips contained in the rack. The rack usually is
formed with eight tips across and twelve tips length-
wise. A de facto standard among pipettor manufac-
turers dictates the spacing between the pipette tips
and the rack.
The present reloading devices are cumbersome and
appear to save only a small percentage of plastic in
their attempt to resolve the reuse of pipette tip
racks.
The present invention reduces the use of plastic
considerably more than the existing racks so that the
user can buy pipette tips loaded in a flat and then,
by using a specially-designed device, load those
stacked pipette tip flats into conventional racks for
use an the laboratory bench.
It is an object of this invention to provide a
loading device for pipette tips that will enable the
user to load tips into conventional racks that are
found in the marketplace.
It is another object of this invention to reduce
the use of plastics in the manufacture of pipette tips
and pipette tip racks.
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It is still another object of this invention to
provide a device that will load multiples of gipette
tip flats into a series of pipette tip,racks.
It is also an object of this inve,r_tion to provide
S a specially configured rack and fla~'-for use with the '
loader.
SUNiMAKY OF THE INVENTION
This invention is for loading a device for
placing a plurality of pipette tips positioned in a
flat into an upstanding pipette tip rack.
The loading device consists of a rectangular base
assembly and a pair of side plates affixed at opposite
ends of the base assembly to extend upwardly there-
from. The de~rice also includes a platform assembly
movably associated with the pair of side plates so
that the platform may move from a. first position
distal of the base to a second position proximate of
the base. Parallel motion means maintain the platform
assembly in a parallel relationship with the base
assembly while the platform moves from a first
position to a second position. The platform assembly
includes release means for retaining a flat on the
platform assembly while the platform assembly is
distal of said base and for releasing said flat in a
predetermined position while said platform moves to
'its second position proximate the base.
The invention also includes a pipette tip rack
having four side walls and an upper surface member
affixed to the upper end of each of the side walls.
The upper surface defines a plurality of holes in a
regular pattern and is formed to receive and hold a
comically shaped pipette. The upper surface member
further includes at least two upstanding bosses, one
boss positioned adjacent one end of said upper surface
and the other boss positioned at a point remote from
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said first boss, and a flat, the flat having
substantially the same shape as the upper surface
' member, said flat defining a plurality of holes each
formed to receive and hold a sonically-shaped pipette
5 tip substantially in the same regular pattern as said
upper surface member holes so that when said flat is
positioned atop said upper surface member, at least
some of said holes in said flat will register with at
least some of said holes in said upper surface member,
said flat also defining at least two register holes
positioned in said flat in substantially the same
relative location on said flat as said two upstanding
bosses on said upper surface member so that when said
flat is placed on said upper surface member and said
two upstanding bosses pass through said at least two
register holes, said holes in said flat register with
said holes in said upper surface member.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an end view of the pipette tip
loading device described herein in its first position;
Figure 2 is an end view of the same pipette tip
loading device in its second position;
Figure 3 is a side view of the pipette tip
loading device shown in Figure 1;
Figure 4 is a top view of the pipette tip loading
device shown in Figure 1;
Figure 5 is an elevation view of one of the side
plates;
Figure 6 is a plan view of the base assembly;
Figure 7 is a sectional view of the base assembly
shown in Figure 6 taken at section line 7-7;
Figure 8 is the lower member of the platform
assembly and the slides;
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Figure 9 is a section view of the lower member
shown in Figure 8 taken at section line 9~9;
Figure l0 is the upper member of the platform
assembly;
Figure 11 :i.s~ a front elevation view of the
pipette tip rack of this invention shown in the
accompanying special box;
Figure 12 is a sectional view of the box shown in
Figure 11 along with a rack and a flat, the figure
showing the inverlti.ve features of the box, rack and
flat;
Figure 13 i~a a side elevation view of the box,
rack and flat; and,
Figure 14 is a section view taken at line 14-14
of Figure 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring nc~w to Figure 1, a pipette tip rack
loading device 10 is shawn. The pipette tip loading
device l0 includE:s a rectangular base member 12. A
pair of side plates 14 and 16 (see Figure 3) are
upstanding of the base member 12. A platform assembly
18 is movably associated with the side plates so that
the platform assembly 18 can move from its first
position as shown in Figure 1 to its second position
as shown in Figure 2. in a parallel relationship to the
base member 12. It should be noted that the platform
assembly is also rectangular and substantially the
same dimensions a.s the base member 12.
Referring to Figure 5, an end view of one of the
two side plates i.s depic;ted. The side plates have a
pair of caroming slots 20 and 22 extending downwardly
from the upper edge 24 thereof. Each of the cam slots
extends dowriwardl.y a predetermined distance d. They
are separated by a second predetermined distance. As
they approach the base member 12, they diverge out-
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wardly for a sec:e>nd distance dZ so that they are
separated by a distance greater than they were at the
upper end 24 of the side plate 14. At the bottom of
the groove, there is a short area 26 wherein the slot
may extend again wertical.ly downwardly toward the base
12. Interspersed :between the two slots 20 and 22 is
a third camming slot: 38. The purpose of the cam slots
20 and 22, briefly stated, is to operate the release
mechanism which will be described in relation to the
upper platform. ''the purpose of cam slot 36 is to act
as a guide for tlze: parallel motion means also to be
described. It is pointed out that the second side
panel 16 is identa.c~al to the first Side panel 14, with
the camming slots :i.n the same position.
Referring now to Figures 6 and 7, the base member
12 is shown. Base member 12 consists of a lower base
30, shown in Figux-e~ 7, two side members 32 and 34,
also shown in Figure 7, and an upper base platform 36,
shown in Figure 6. Upper base member 36 is not as
wide as the lower base member 30 as evidenced in
Figure 6. This smaller dimension creates openings 39
and 40 between the side members 14 and 16. The
openings 39 may be enlarged on one-half of the base
member at 40, as ~;hown :in Figure' 6. The purpose of
the openings 39 and 40 is to permit the parallel
motion members 42 and 44 to extend downwardly into the
slots 39 and 40.
Parallel motion members 42 and 44 are best seen
in Figure 1. TheVV are identical in structure and form
an X-type or scissors mechanism, as can be seen in
Figure 1. 'The t:wo members 42 and 44 are pivotably
affixed one to the other by an axle 46 so that they
may have a scissors-type motion. Axle 46 extends
outwardly into s:Lot: 38 when the device is assembled
(see Figures 1 and 2).
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At the lower end of the scissors members 42 and
44 are rods 48 and 50, which extend across underneath
the upper base platform 36 to connect to the corre-
sponding scissors members 42 and 44 at: he opposite
end of the rack, as shown in Figure 1. ~;fhe second set
of scissors is identical to the fire's set. The upper
end of scissors 42 and 44 are interconnected to the
identical pair of scissors 42 and 44 on the opposite
side of the rack by pin members 52 and 54. Stretched
between pin members 52 and 54 is a resilient means,
such as a spring 56, or an elastomeric member, thereby
biasing the scissors device to the closed,position, as
shown in Figure 1.
The upper platform assembly 18 consists of two
members affixed one to the other. A lower member 58
is shown in Figure 8. The lower member 58 is
rectangular in shape arid has extending outwardly
therefrom two bosses 60 and 62, which are adapted to
ride in slots 38 on each of the two ends, 14 and 16.
A rectangular opening 64 is centered on the lower
piece 58. Opening 64 is sufficiently large to let a
pipette tip flat (to be described) pass therethrcugh
in a flat orientation.
Lower member 58 has two cut-out or depressed
areas 79 shown in section in Figure 9. These cut-outs
79 extend across the width of lower member 58 so that
slides 76 and 78 may move laterally toward and away
from opening 64. When the upper member 82 of platform
18 and the lower member are assembled, slides 76 and
78 are movably positioned as shown in Figure 8.
With the slides 76 and 78 in their closed posi-
tion, a pipette tip flat (to be described) will not
pass through the opening 64. In their open position,
that is, drawn laterally away from the opening 64, the
pipette tip flat will pass through the opening 64.
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Fitted on either end of slides 76 and 78 are bosses
80, which in fact are cam followers for the cam slots
20 and 22.
The upper member of the platform 18 is a rec
tangular piece 82, as shown in Figure 10. The upper
member 82 corresponds to the lower member 58, with the
exception that the opening in the upper surface
thereof may he slightly smaller, but is at least as
large as the pipette tip flat that is passed there
through. Again, bosses 84 are located on the sides of
the top platform 82 so that they register with the
previously described bosses 60 and 62 located
respectively on the lower platform. The opening in
the upper platform 82 is beveled at 86 (see Figure lOD
to facilitate a flat passing through the opening.
When assembled, the platform assembly 18 may be
prevented from separating from the rest of the
assembly by the closures in the slots 20, 22, and 38,
as shown in Figure 5. The platform assembly 18 is
prevented from moving upwardly beyond that paint, but
is biased upwardly by resilient member 56 and by the
parallel motion action of the scissors 42 and 44.
Referring to Figure 4, an upper view of a pigette
tip flat 90 is illustrated positioned in the tip
loader 10. In the side view in Figure 3, this same
flat 90 is located in the rack with attendant pipette
tips 92. A second flat 94 is shown for illustration
purposes only, along with its plurality of pipette
tips 96. The flats 90, best shown in Figure 4,
contain a plurality of holes 98 in a regular pattern,
for example, eight rows of twelve holes each, in which
pigette tips, such as pipette tips 92 and 96, may be
positioned. These holes are carefully registered with
a corresponding set of regular holes in a pipette tip
rack 100, which is shown in Figure 3. Pipette tip
WO 95!33564 PC'f/US95f03576
rack 100, as noted above, has an equal number of holes
97 in its upper surface 9i, the holes 97 positioned in
the same regular pattern so that the holes 97 in the
rack 100 will register with the holes 98 in rack 90.
5 Flat 90 also includes two register holes 200 and '
202 at opposite ends of flat 90. .,These two register
holes are located at the same rela~ive position to the
holes 98 as two corresponding upstanding bosses 204
and 206 located on the upper surface of pipette tip
i0 rack 100 isee figures 2 and 3). These register holes
and upstanding bosses serve to hold flat 90 in
register after it is positioned atop pipette tip rack
100.
Rack 100 must be positioned,properiy in loading
device LO so that when the device is operated, a flat
90 leaded with pipette tips 92 may be positioned an
rack 100 with the pipette tips 92 meshing properly
with rack 100. Accordingly, rack 100 includes an
orifice or slot 208 !see Figure 3) located near the
top of one of the four upstanding sides of the rack.
This slot 208 receives a tongue 210 that is rigidly
mounted on a wall 102 that is affixed to and extends
between sidewalls 14 and 16. Orifice or slot 208 is
purposely made with its horizontal dimension only
slightly larger than tongue 210 to effect horizontal
registration. The rack 100 is prevented from being
skewed in loader 10 as the tongue is affixed to a
horizontal stop member 212 so that rack 100 may abut
against the stop member when correctly positioned.
The vertical dimension of slot 208 is sufficient so
that rack 100 may be loaded while it is in a box 220
(see Figure 11).
Box 220 has inside dimensions slightly larger
than rack 100; that is, the inside length of box 100
is slightly longer than rack 100 and the inside width
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of box 100 is slightly wider than rack 100. This
results in a snug fit when a rack is positioned in the
box. Further, slot 208 will still register with
tongue 210 just as stop member 212 will abut rack 100
and not box 220 with the rack 100 in loader 10 as the
upper portion of the rack extends above the lip of the
box.
Box 220 includes a cover 222 hingedly fixed to
box 220 so that the cover may be removed (see Figure
13) by fully opening the cover to its 180° position
and then separating it from box 220. Also included is
a latch device including a socket 224 on box 220 and
a latching member 226 that folds over socket 224 when
pin 228 seats in socket 224 to lock the cover on box
220.
Located on the inner surface 230 of the top of
cover 222 are at least two lugs 232 which extend
downwardly when cover 222 is closed so that each lug
232 will contact at least one and preferably two
pipette tips in rack 100 and flat 90 to insure that
flat 90 is registered with rack '100 by means of at
least pins 204 and 206 registering with holes 200 and
202 (see Figure 12).
In operation, a flat 90 or a plurality of flats
90, 94 (see Figure 3) are placed in the opening in the
upper platform i8. At this point, they are resting on
the two slides 78 and 76 (see also Figure 8) and will
not pass through the opening in the lower portion of
the upper platform. Further, the bevel 86 in the
upper member of platform 18 insures that the holes 98
in the flat 90 are registered with a rack 100. Rack
100 is similarly held in a predetermined position by
tongue 210. The top platform 18 is depressed manually
so that the parallel motion arms 42 arid 44 separate,
as best illustrated in Figure 2. As the cams 80 pass
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down the camming slots 20 and 22, they separate and
withdraw the slides 76 and 78 sa that the pipette tips
90 register with the holes in .: 'he pipette tip rack
100. As the structure reaches ,its lowest position, as
S shown in Figure 2, the slides 78 and 76 fully open and
the flat 90 is released to rest upon the pipette tip
rack 100, which is shown in phantom in Figures 1 and
2. Concurrently, the registration pins 204 and 206
penetrate holes 200 and 202 to hold the flat in
position. If the rack is in a box 220 when loaded,
lugs 232 will insure the flat remains in rack 100 in
the proper gosition when cover 222 is closed.
At this point, the second flat 94, as can be seen
in Figure 2, is above the diverging portions of the
caroming slots 20 and 22, so that as the platform
assembly 18 is urged upwardly by the resilient member
52, bringing together the scissors 42 and 44, the
slides 76 and 78 are caromed inwardly by those slots 20
and 22 to pick up the next pipette tip flat 94 as the
assembly expands into its upper position, shown in
Figure 1. At that point, the pipette tip rack IDD may
be withdrawn from the device as the tig ends in the
next flat 94 do not extend downwardly far enough to
rest in the flat just positioned on the top of rack
100. It should be noted that if the rack 100 is in a
box 120 when loaded, the cover of the box 220 will be
opposite the tongue 210 or the cover may be removed.
The technician may then take rack 100 off to a
workspace to utilize the tips placed therein in the
assembly.
~7nce the tips are exhausted in rack 100, the flat
90 can be placed in a salvage bin while the rack 100
is returned to the device 10 to have a second or
another set of pipette tips and associated flat
inserted therein.
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The advantage of this assembly is that the
pipette tip rack may be used over and over again,
while the only thing returnable to the manufacturer
are the flats 90 and, if desired, the used pipette
tips 92 and 96. This saves the manufacturer in that
the pipette tip racks need nat be manufactured equal
to the pipette tips, but rather a flat is manufactured
containing the requisite number of pipette tips. The
user is saved the chore of placing pipette tips 90
into the rack 100 by hand, which has been the practice
in the past. Further, rather than sending back
pipette tip racks, which some pipette tip users had
been doing, the pipette tip racks may be recycled
right in the laboratory.
This invention is limited only by the appended
claims which follow.
